It’s important to ensure the content is informative and relevant to the caller. And the rule ‘less is more’ very much applies to writing for the ear. It’s important to keep the sentences short and to the point. A popular way to get a message across is follow this structure: Introduce the topic in the first sentence e.g. Did you know that BusinessCo now offers no contract plans for hosted PBX and business VoIP? Explain how the information will benefit the caller in the second sentence e.g. And that means complete flexibility for your business and no long-term commitments. Wrap up with a call to action in the third sentence e.g. To find out more, visit our website businesspbx.com.au or speak to one of our Business Consultants when you come off hold.
Finally, take into account the reduction in quality that goes hand in hand with hold music. The audio quality is—at best—24 times worse than that from a CD. Yes, we just said CD. The public telephone network wasn’t built with HD music in mind. Thankfully for OnSIP customers, we provide HD radio for VoIP music on hold. That said, your company might have top of the line audio quality, but if clients call in from an old landline or cell, they might hear some distortion.

Typically, if you what to use copyrighted music in your project, you must obtain two licenses - a Sync (Synchronization) license from the publisher and a Master license from the recording label.
While you need to adapt your writing style for screenwriting, you also need to realize there are additional production steps to recording an on hold message. You need to find someone who has the right voice for the job, and who can read your script well.